This formula is satisfiable because if we set to b to true and a to false, then the whole formula is true. All other assignments make the formula false, but it doesn't change that the formula is satisfiable as long as there is at least one assignment makes the formula true.
ВСУ запустили «Фламинго» вглубь России. В Москве заявили, что это британские ракеты с украинскими шильдиками16:45
。同城约会对此有专业解读
Hilary Knight earlier this week said she doesn’t want to let what she called a “distasteful” joke by Trump get in the way of a historic performance by American women at the Winter Games. Players for both U.S. teams have been uniform in saying how much they bonded in the athletes’ village in Milan and supported each other on their runs to gold.
19th Century gold dentures
优势：时间复杂度O(d*(n+k))，d为位数，适合位数少的整数